The present invention relates to locking structures of connector assemblies, particularly to a locking structure of a connector assembly having a plug and a receptacle that are fitted to each other along a fitting direction.
A connector assembly having a locking structure is illustrated in IEC61169-54 ed 1.0, RF and Microwave passive components, p 14, FIG. 5 Quick lock type (Literature 1). As shown in FIG. 15, the connector assembly has a plug 1 and a receptacle 2. When the plug 1 is slid with respect to the receptacle 2 in the +X direction which is the fitting direction, a plug shell 3 of the plug 1 is fitted into a receptacle shell 4 of the receptacle 2, thereby establishing the fitted state between the plug 1 and the receptacle 2.
A sleeve 5 is disposed on the outer periphery of the plug shell 3. In the fitted state between the plug 1 and the receptacle 2, a part of a C-ring 6 housed in a C-ring housing groove 5A formed in the inner periphery of the sleeve 5 is inserted in a locking groove 4A formed in the outer periphery of the receptacle shell 4.
The C-ring housing groove 5A formed in the inner periphery of the sleeve 5 has a vertical surface 5B being perpendicular to the fitting direction and facing in the −X direction, the locking groove 4A of the receptacle shell 4 has a vertical surface 4B being perpendicular to the fitting direction and facing in the +X direction, and the +X direction-side and −X direction-side ends of the C-ring 6 form vertical surfaces 6A and 6B being perpendicular to the fitting direction and facing in the +X and −X directions, respectively.
By bringing the vertical surface 6A of the C-ring 6 at its +X direction-side end into contact with the vertical surface 5B of the sleeve 5 and the vertical surface 6B of the C-ring 6 at its −X direction-side end into contact with the vertical surface 4B of the receptacle shell 4, the fitted state between the plug 1 and the receptacle 2 is locked. In other words, even when an external force acts to separate the plug 1 and the receptacle 2 in the fitted state from each other, the configuration above prevents the plug 1 from coming off the receptacle 2.
The distance A between a corner 5C of the vertical surface 5B of the sleeve 5 and a corner 4C of the vertical surface 4B of the receptacle shell 4 in the fitting direction and the distance B therebetween in the radial direction perpendicular to the fitting direction are specified to certain values as the standards, as stated in Literature 1 above.
The plug 1 further includes a coupling 7 disposed on the outer periphery of the sleeve 5 to be slidable in the fitting direction. When the coupling 7 is slid in the −X direction with respect to the plug 1 in the fitted state, this causes a turning-back portion 7A formed on the radially-inward side of the coupling 7 to exert a radially-outward force toward the C-ring 6 so that the ring diameter of the C-ring 6 elastically increases, whereby the vertical surface 6B of the C-ring 6 at its −X direction-side end is separated from the vertical surface 4B of the receptacle shell 4, thus the lock of the fitted state between the plug 1 and the receptacle 2 is released. Accordingly, the plug 1 can be come off the receptacle 2.
Meanwhile, when the plug 1 and the receptacle 2 in the fitted state are being separated from each other, a force F1 directed in the −X direction is exerted from the vertical surface 5B of the sleeve 5 to the vertical surface 6A of the C-ring 6 at its +X direction-side end, and at the same time, a force F2 directed in the +X direction is exerted from the vertical surface 4B of the receptacle shell 4 to the vertical surface 6B of the C-ring 6 at its −X direction-side end. Those forces F1 and F2 are away from each other by about the distance B in the radial direction perpendicular to the fitting direction and accordingly, a couple of forces occurs at the C-ring 6. This couple forms a force FA that acts to deform the +X direction-side end of the C-ring 6 in the radially-outward direction, and when a force acting to separate the plug 1 and the receptacle 2 from each other increases, the C-ring 6 may be plastically deformed beyond the limit of elasticity and get broken.